Thimble ring for shackles



V. LARSON ETAL THIMBLE RING FOR SHACKLES may m W55 Filed Sept. 15, 1952 ATTORNEYS United States Patent THIMBLE RING FORSHACKLES Victor Sjunne Larson and Donald ELLarson, San Jose, Calif.

Application September 15, 1952, SerialNo. 309,636

1 Claim. (Cl. 294-78) The present invention relates to a thimble ring, and pertains more particularly to a thimble ring for use on heavy shackles of the type used in logging and other heavy work.

in logging operations in different parts of the country, particularly in the Pacific Northwest, after the trees are felled, and cut into logs of required length, the logs are taken out of the woods by tractors or drag lines. When using tractors, a logging arch, which comprises a tilted boom mounted on crawler type treads and drawn by a crawler type tractor frequently is used. Each log is provided with a short individual cable called a choker which is looped around one end of the log with a slip connection provided by an eye splice or socket.

The logs then are drawn from the place where they are felled into a position near the arch by a cable, which is operated from a winch on the tractor and runs through a fair lead at the upper end of the arch boom. When several of the logs thus have been assembled near the arch, the chokers are secured to a single large hook on the end of a short length heavy chain, and this chain is secured by a pear link, as it is called, due tovits shape, and a shackle, to the tractor cable. The tractor cable then is drawn in through the fair lead by means of the tractor winch to elevate one end of the group of logs, which then are dragged to a loading station where they are loaded on trucks or trains, or are skidded into a stream for transporting to a mill.

The connection of the tractor cable to the shackle is made by means of an eye splice formed in the end of the cable, and secured to the shackle by removing the shackle pin, inserting the bight of the eye splice into the open end of the shackle, and then replacing the shackle pin to pass through the eye splice.

This point of attachment of the heavy shackle to the tractor cable is a frequent source of trouble, since in use the severe stresses to which it is subjected tend to flatten the cable against the shackle pin and to distort and crystallize the cable strands at the bight of the eye splice. Failure of the cable at this point requires either that the entire cable be replaced, or that the eye portion thereof which is attached to the shackle be cut off and the cable respliced. During the period of time required for this repair, the tractor is incapacitated, with a resultant loss of time and money to the operator.

The present invention contemplates the provision of an improved split thimble ring for use on a heavy shackle pin for attachment to a cable. The invention also provides a thimble ring for mounting on the pin of a heavy shackle which facilitates insertion in, and removal of a thimble from the eye of a cable to which it is secured.

A further object is to make a shackle thimble ring of two reversely notched and interfitted portions.

The invention also provides for the making of a shackle thimble ring in two interlocking similar half portions.

These and other objects of the invention will be apparent from the following description and accompanying drawings wherein:

Fig. l is a perspective view of a logging arch employshackle and thimble ring shown in Fig. 2, portions thereof being broken away on a median plane.

Fig. 4 is a further enlarged perspective view of the two'halves of the thimble ring shown in Figs. 2 and 3 as "they would appear separated axially from each other.

In the drawings, Fig. 1 shows a conventional crawler type logging arch 10 drawn by a crawler type tractor 11 having a winch 12 mounted thereon. A cable 13 from the winch passes through usual guides 14 and 15 on the boom 17 of the arch. A heavy shackle 18 is secured to an eye 19 spliced in the end of the cable 13. The shackle 18 is connected by a large, pear-shaped ring 20 of a conventional type to a heavy chain 21. Chain 21 has a large hook 22 secured to its outer end by a con ventional shackle 23. The hook 22 is of a type to which several eye sockets 24 of conventional choker cables 2:5 may be secured to hoist the forward ends of a group of logs 27 and drag them out of the woods.

The shackle 18 (Figs. 2 and 3) preferably has the shackle pin 18 thereof of the flushhead type, so as not to interfere with its free passage through the fair lead 29 of the arch 10. An externally grooved, composite thimble ring 30 embodying the present invention comprises two preferably similar sections 31 and 32. These sections are provided with axial openings 33 of a size to fit onto the shank 28' of the shackle pin 28.

Each of the thimble half members 31 and 32 has a flat outer end face 34 fitting flush against corresponding flat inner faces 35, 35 of end lugs 36, 36 of the shackle 18. To form the external groove 3% in the thimble ring 30, each shackle half portion 31 and 32 tapers toward its inner end, and its periphery is curved concavely to conform with the cross sectional shape of the cable 13, when the thimble ring is inserted in the eye splice 19 of the cable as shown in dotted lines in Fig. 3.

The inner or adjoining ends of the thimble half portions 31 and 32 are notched, as shown at 37, 37, to leave outstanding projections or lugs 38, 38. The lugs 33, 38 preferably are of the same size as the notches 37, 37 so that the lugs of half portion 31, for example, of the ring 30 will fit into the notches 37, 37 of the other half portion 32 thereof. Thus the two half portions 31 and 32 of the thimble ring may be fitted, from opposite sides, into the eye 19 of a cable after it has been formed without spreading the eye with resultant deformation and damage to the cable.

Preferably the lugs 38, 38 extend beyond the median plane of the assembled thimble ring 30, in a direction transversely of the axis thereof. Thus the bottoms of the notches 37, 37, and the tops of the lugs 38, 38 fitted therein terminate on opposite sides of such median plane.

In the event that it should become necessary to remove the shackle from the eye of a cable after the cable has been in use for some time, the shackle pin 23 may be removed and the thimble ring 36 may be withdrawn from the shackle. The thimble ring 30 then may be readily removed from the eye 19 of the cable by separating the two thimble ring halves 31 and 32. This arrangement prevents the serious damage which frequently may be caused to the eye of a cable when attempting to remove some former types of thimble ring after the cable has been in use for some time.

While we have illustrated and described a pr ferred embodiment of the present invention, it will be understood however, that various changes and modifications may be made in the details thereof without departing from the spirit and scope of the invention as set forth in the appended claim.

as new and desire to protect by Letters Patent is defined in the following claim.

We claim t In combination, a strong U-shaped shackle body, a lug formed on the end of each leg thereof, said lugs having co-axial holes therethrough, the wall around one of said holes being threaded, a shackle pin insertible through one of said holes and threaded for screwing into the threaded Wall of the other of said holes, the inner faces of said lugs being spased apart, a two-part thirnble ring having an axial hole therethrough of a diameter closely to receive the shackle pin therein, the ring being of a length, and the ends thereof being formed for close, interfitted insertion between the inner faces of said shackle lugs, said two-part having a peripheral groove therearound for receiving an encircling cable eye, the ring being divided into'two parts on a plane perpendicular to the axial hole therethrough for lateral separation of its two parts upon withdrawal of the ring from the shackle body to facilitate removal of the ring from a cable eye formed thereon, and alternate axially extending lugs and notches formed on the two ring portions for relative interfitted relation to extend beyond the center of the cable receiving groove of the assembled ring to provide'support at the bottom of the groove for a cable ey-e formed thereon.

References Cited in the file of this patent UNITED STATES PATENTS 625,924 

